The present application claims the benefit under 35 U.S.C. §119 of Provisional Application Ser. No. 60/926,971 which was filed on Apr. 30, 2007. The above-referenced application is incorporated by reference herein.
Electronic multiple pole multiple throw (MPNT) switches are widely used. An MPNT switch is a switch having M poles (P) and N throws (T), where M>1 and N>1. A pole and a throw are coupled to one another by a path that includes at least one switching element. An electrical signal is routed on a path between one of the M poles and one of the N throws when that path is in a conducting state. In a single transmission mode MPNT switch, only a single pole-throw path is conducting at one time. In a multiple transmission mode switch, more than one pole-throw path may be conducting at the same time.
A switch having multiple inputs and multiple outputs is an example of an MPNT switch. An antenna switch for a wireless communication device is one application for an MPNT switch. In one example of a 2P2T (DPDT) antenna switch, a first pole is coupled to a receiver, a second pole is coupled to a transmitter, a first throw is coupled to a first antenna, and a second throw is coupled to a second antenna. Depending upon the state of the switching elements within the paths, the transmitter may be operably coupled to one of the antennas, or the receiver may be operably coupled to one of the antennas. MPNT switches having greater numbers of poles or throws, such as 2P4T (DP4T) or 3P3T switches, may be used in more complex devices such as communication devices that include additional antennas or multiple receivers or transmitters. A multiple transmission mode MPNT switch may be used in a communication device that operates in multiple input multiple output (MIMO) mode. In MIMO mode, two or more paths are conducting at the same time, thereby enabling two or more antennas to transmit or receive signals at the same time.